From my Tweeting for Engagement presentation.
Four of the top things that Twitter is best used for: 
- Conversations: speaking directly with your followers and the people you follow. Social media is all about connecting with others – everyone from your friends to partner organizations to the competition – and it’s a good way to keep updated on what is going on with everyone around you, and to keep up the communication with them so they know what you are doing as well.
- Sharing stories and links: this is a great opportunity to link to your website articles or to news stories etc. Overlap all of your forms of social media (including blog and online newsletters), and help your partner organizations out by sharing their links, too.
- Building community: From Twitter.com,
Twitter lends itself to cause and action. Every day, we are inspired by stories of people using Twitter to help make the world a better place in unexpected ways … enables us to learn about or show our support for positive initiatives that might have otherwise gone unnoticed.
- Brand awareness and engagement! Twitter is ideal for building brand awareness and engaging target audiences. By posting updates, links, and Retweets that are in line with your mandate, you’ll be continually reinforcing your brand in the Twitterspehere. You can also use Twitter to speak with your supporters about what they are interested in to better understand your audience and connect with them on new levels.
What do you use Twitter or other forms of social media for? Share in the comments section below!